{ config, pkgs, ... }: with pkgs.lib; let inherit (pkgs) cups; logDir = "/var/log/cups"; modprobe = config.system.sbin.modprobe; cfg = config.services.printing; # Here we can enable additional backends, filters, etc. that are not # part of CUPS itself, e.g. the SMB backend is part of Samba. Since # we can't update ${cups}/lib/cups itself, we create a symlink tree # here and add the additional programs. The ServerBin directive in # cupsd.conf tells cupsd to use this tree. bindir = pkgs.buildEnv { name = "cups-progs"; paths = cfg.drivers; pathsToLink = [ "/lib/cups" "/share/cups" ]; postBuild = '' ${pkgs.coreutils}/bin/mkdir -p $out/lib/cups/backend ${pkgs.coreutils}/bin/ln -s ${pkgs.samba}/bin/smbspool $out/lib/cups/backend/smb # Provide support for printing via HTTPS. ${pkgs.coreutils}/bin/ln -s ipp $out/lib/cups/backend/https ${cfg.bindirCmds} ''; }; in { ###### interface options = { services.printing = { enable = mkOption { default = false; description = '' Whether to enable printing support through the CUPS daemon. ''; }; bindirCmds = mkOption { default = ""; description = '' Additional commands executed while creating the directory containing the CUPS server binaries. ''; }; cupsdConf = mkOption { default = ""; example = '' BrowsePoll cups.example.com LogLevel debug ''; description = '' The contents of the configuration file of the CUPS daemon (cupsd.conf). ''; }; drivers = mkOption { example = [ pkgs.splix ]; description = '' CUPS drivers (CUPS, gs and samba are added unconditionally). ''; }; }; }; ###### implementation config = mkIf config.services.printing.enable { environment.systemPackages = [cups]; services.dbus.packages = [cups]; environment.etc = [ # CUPS expects the following files in its ServerRoot. { source = "${cups}/etc/cups/mime.convs"; target = "cups/mime.convs"; } { source = "${cups}/etc/cups/mime.types"; target = "cups/mime.types"; } ]; jobs.cupsd = { description = "CUPS printing daemon"; startOn = "started network-interfaces"; stopOn = "stopping network-interfaces"; preStart = '' mkdir -m 0755 -p ${logDir} mkdir -m 0700 -p /var/cache/cups mkdir -m 0700 -p /var/spool/cups # Make USB printers show up. ${modprobe}/sbin/modprobe usblp || true ''; exec = "${cups}/sbin/cupsd -c ${pkgs.writeText "cupsd.conf" cfg.cupsdConf} -F"; }; services.printing.drivers = [ pkgs.cups pkgs.ghostscript ]; services.printing.cupsdConf = '' LogLevel info SystemGroup root Listen localhost:631 Listen /var/run/cups/cups.sock # Note: we can't use ${cups}/etc/cups as the ServerRoot, since # CUPS will write in the ServerRoot when e.g. adding new printers # through the web interface. ServerRoot /etc/cups ServerBin ${bindir}/lib/cups DataDir ${bindir}/share/cups AccessLog ${logDir}/access_log ErrorLog ${logDir}/error_log PageLog ${logDir}/page_log TempDir /tmp Browsing On BrowseOrder allow,deny BrowseAllow @LOCAL DefaultAuthType Basic Order allow,deny Allow localhost Order allow,deny Allow localhost AuthType Basic Require user @SYSTEM Order allow,deny Allow localhost Require user @OWNER @SYSTEM Order deny,allow AuthType Basic Require user @SYSTEM Order deny,allow Require user @OWNER @SYSTEM Order deny,allow Order deny,allow ''; }; }